title: Linking rhizoplane pH and bacterial density at the microhabitat scale.
abstract: Ion-selective microelectrodes and a novel micro-sampling technique were used to investigate the relationship in field soil between Brassica napus rhizoplane pH and bacterial density at a spatial scale approximating a microhabitat. Bacterial densities were observed to increase with decreasing pH, rhizoplane pH measurements varied by up to 1 pH unit over a distance of 1 mm and the mean pH of the rhizoplane at the root base varied by more than 1 pH unit between plants. These findings highlight the appropriateness of investigating the interactions between bacterial communities and their environment at the micro-spatial scale and the utility of the micro-sampling method.
authors.affiliation: Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK. paul.dennis@scri.ac.uk
authors.forename: Paul G
authors.initials: PG
authors.lastname: Dennis
authors.forename: Penny R
authors.initials: PR
authors.lastname: Hirsch
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Smith
authors.forename: Richard G
authors.initials: RG
authors.lastname: Taylor
authors.forename: Eugenia
authors.initials: E
authors.lastname: Valsami-Jones
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Miller
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D001431:Bacteriological Techniques; D029688:Brassica napus / Q000382:microbiology; D017753:Ecosystem; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability; D008839:Microelectrodes; D018517:Plant Roots / Q000382:microbiology*; D012988:Soil Microbiology